Cr(VI) is a common pollutant in wastewater and many previous studies using biochar-based materials as adsorbents for their well adsorption performance. However, the preparations of some biochars are complex, uneconomical, and with a poor reusability, which set limit on their practical application. Here, a mesoporous-rich biochar-based Cr(VI) adsorbent was easily prepared by pyrolyzing the badam-shell that in situ activated by concentrated phosphoric acid (H₃PO₄), with the aim of improving the removal effect of Cr(VI) in an aqueous solution. The partition coefficient (PC) was used to compare the performance of adsorbents more comprehensively, and the maximal PC value of the activated badam-shell biochar (ABSB) was 978.8 L g^-1. In addition, its maximum adsorption capacity was 276.6 mg g^-1. ABSB has a superior removal effect on the relatively low concentration of Cr(VI) (≤ 50 mg L^-1), and residual Cr(VI) can meet the maximum emission standard (< 0.5 mg L^-1) of industrial wastewater. The specific surface area of ABSB (1359.5 m² g^-1) was approximately four times that of pristine badam-shell biochar (BSB) (371.87 m² g^-1). The adsorption mechanisms involved were redox, complexation, electrostatic attraction and hydrogen bonding. The removal rate of Cr(VI) on ABSB remained at 81.6% after six cycles of adsorption–desorption. In a word, our study provides a simple, economic, and environmental method in fabricating the new adsorbent, which is highly promising and will not cause secondary pollution.

六价铬是废水中的常见污染物，许多以前的研究都使用生物炭基材料作为吸附剂，以实现良好的吸附性能。然而，一些生物炭的制备复杂，不经济且可重复使用性差，这限制了它们的实际应用。在此，通过热解由浓磷酸（H ₃ PO ₄）原位活化的巴达姆壳，可以容易地制备富含介孔的生物炭基Cr（VI）吸附剂，目的是提高Cr（VI）的去除效果。 ）在水溶液中。分配系数（PC）用于更全面地比较吸附剂的性能，活化的巴达姆壳生物炭（ABSB）的最大PC值为978.8  L  g ^-1。另外，它的最大吸附容量为276.6 毫克 克^-1。ABSB对较低浓度的Cr（VI）（≤50  mg  L ^-1）具有优异的去除效果，残留的Cr（VI）可以满足工业废水的最大排放标准（<0.5  mg  L ^-1）。ABSB的比表面积（1359.5 m ² g ^-1）约为原始巴达姆壳生物炭（BSB）（371.87 m ² g ^-1）的四倍）。涉及的吸附机理是氧化还原，络合，静电吸引和氢键。经过六个吸附-解吸循环后，ABSB上的Cr（VI）去除率保持在81.6％。简而言之，我们的研究提供了一种简单，经济和环保的方法来制备这种新型吸附剂，这种方法极有希望且不会造成二次污染。